Valentino Rossi has opted to continue riding Ducati’s radically revamped GP11.1 at Laguna Seca, the Italian resisting the temptation to revert back to the older GP11 model.
Rossi had requested the chance to ride the GP11 having failed to make any major step forward with the GP11.1 Desmosedici he first ran in Assen last month.
But he preferred to exclusively ride the GP11.1 in California on his way to another difficult day of practice on the shortest track on the MotoGP calendar.
The 32-year-old set a best time of 1.23.369 but he was still 1.313s adrift of former factory Yamaha team-mate Jorge Lorenzo, who topped the timesheets with a 1.22.056.
The nine-times world champion said: "Both our bikes were the GP11.1, so we continue with this. We spoke with Jerry (Burgess) and for us there is not a lot of difference. So maybe it is better to concentrate on the new bike and try to improve our potential. Nicky (Hayden) made the comparison and like we expect, it is more or less a very similar feeling."
Rossi said he was faster using the GP11.1 he raced to a disappointing ninth place in Germany last weekend, which featured a heavily modified weight distribution setting.
He added: "We continued with the setting of Germany we used in the race because we did such a big modify with the weight distribution. The other bike had a more normal setting. I confirmed that the bike of the Sachsenring race is a bit better. Now we are out of balance with the front, so we need to find the right balance and also find the better line, but we can improve."